VPP-1576: nsim-plugin coverity issues
VPP-1576: nsim-plugin coverity issues

Change-Id: I832e780b00955e01871874544f3d0afc553b75f7
Signed-off-by: Dave Barach <bfcdf3e6ca6cef45543bfbb57509c92aec9a39fb@barachs.net>

chrisy/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp,FDio/vpp,FDio/vpp,vpp-dev/vpp,vpp-dev/vpp,FDio/vpp,vpp-dev/vpp,FDio/vpp,FDio/vpp,chrisy/vpp,vpp-dev/vpp,chrisy/vpp,chrisy/vpp,vpp-dev/vpp,chrisy/vpp,FDio/vpp,chrisy/vpp,chrisy/vpp,FDio/vpp,vpp-dev/vpp